I. Field of the Invention
The present invention relates to medical simulation. In particular, the present invention relates to life support simulation apparatuses capable of responding realistically to therapeutic interventions.
II. Background of the Invention
The goal of Life Support ("LS") in case of a cardiac arrest is to partially assist (in the case of heart or respiratory failure) or completely assume (in the case of cardiac or respiratory failure) the function of the heart and lungs in providing perfusion of oxygenated blood to the brain, heart, kidney, liver, and other vital organs. In the case of cardiac or respiratory arrest the goal of life support therapy is to restore spontaneous breathing and cardiac rhythm. Life support therapy takes many different forms and is administered according to a variety of clinical protocols, guidelines, algorithms, including Basic Life Support ("BLS"), Advanced Cardiac Life Support ("ACLS"), and Advanced Trauma Life Support ("ATLS"), for example. These different forms of life support are utilized by many health care professionals, including emergency medical technicians, paramedics, and physician nurses, and health care technicians who work in the emergency department, intensive care units, operating rooms, and other acute care settings in the hospital. Representative therapies include, but are not limited to, external cardiac massage ("chest compression"), artificial ventilation, and fluid and drug administration.
The return of a cardiac Thythm can be evaluated in several ways, including palpation of peripheral pulses, auscultation of heart sounds, measurement of systemic blood pressure, assessment of the electrocardiogram, and with data from the pulse oximeter. The return of spontaneous breathing can be evaluated in several ways, including assessment of gas movement, observation of chest movement, auscultation of breath sounds, measurement of respiratory carbon dioxide with a capnograph, and with data from a pulse-oximeter. The return of cardiac rhythm, spontaneous breathing and the successful perfusion and oxygenation of the brain depends on the physiologic state of the patient and on the combined effect of the therapeutic interventions. Several interacting physiologic and pharmacologic subsystems play a role in this determination, including the cardiovascular, pulmonary, systemic gas uptake and distribution, drug transport (pharmacokinetics), drug effects (pharmacodynamic), and oxygen supply-demand balances in the heart and brain.
Health care professionals face many challenges in leaning and practicing life support therapies. The environment is often new and unfamiliar and usually involves the use of technologically advanced medical instruments and devices. Mistakes can threaten the life of the critically ill patient, so learning by "hands-on" experience is difficult (and difficult to justify). The life support system described herein allows for the repeated practice of life support interventions and protocols, without risk to real patients. The invention elaborates on a full-scale human patient simulator ("HPS") by adding external cardiac massage capabilities and providing the physiological and pharmacological models to simulate the patient's responses to this and other life support therapeutic interventions.
A major benefit of an integrated HPS is that it allows realistic action/reaction interplay between the actions of the trainee, responses of the simulated patient, data shown on the monitors and subsequent actions by the trainee. Another feature of the HPS is that its software and hardware reflect the self-regulating aspects of human physiology. For instance, in a non-self-regulating system, an awkward input situation would invariably lead to physiologically implausible behavior from the system or such stimuli would result in an inability of the system to handle the input at all. A self-regulating system is more robust in the accommodation and simulation of unplanned events because it will still provide an appropriate response.